The present invention relates in general to mineral mining installations and, more particularly, to apparatus for controlling the position of a mineral mining or winning machine movable along guide means.
For this purpose, it is know to use a form of control apparatus with hydraulic piston and cylinder units connected between the guide means, more particularly a conveyor having a guide on its mineral face side, and elongate beams pivotably in relation to the conveyor and displaceably guided on roof supports. Examples of known apparatuses are described in U.S. Pat. Nos. 4,045,089 and 4,186,969 in German patent specification Nos. 2319910, 2535325 and 2942089 and in German Gebrauchsmuster No. 6603643.
Various problems are encountered with know apparatuses, For example, it is not always possible to control the machine properly especially when the conveyor is tilted to cause the machine to climb. Also when the goaf side of the conveyor is raised from the floor fire material, such as coal dust, can pass beneath the raised conveyor and find its way into the roof support zone. Such material can adversely affect the operation of the roof supports and also represents a loss of material. A general object of the present invention is to provide an improved form of control apparatus.